ML19351A162

LER 81-045/03L-0:on 810529,as-found Data for Summing Amplifier Found Out of Tolerance High During Protection Channel 1 Periodic Surveillance Test.Caused by Instrument Drift.Summing Amplifier Recalibr

ML19351A162
Person / Time
Site:	North Anna
Issue date:	06/22/1981
From:	Cartwright W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML19351A161	List: ML19351A160 ML19351A162
References
LER-81-045-03L-01, LER-81-45-3L-1, NUDOCS 8106260157
Download: ML19351A162 (2)

Text

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L AR REGULATORY COMMISSIoy h '

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LICENSEE EVENT REPORT CONTROL BLOCK /-/ / / / / / (1) (PLEASE PRINT OR TYPE ALL' REQUIRED INFORMATION)

/0/1/ /V/A/N/A/S/2/ (2) /0/0/-/0/0/0/0/0/-/0/0/ (3) /4/1/1/1/1/ (4) / / / (5)

LICENSEE CODE- LICENSE. NUMBER LICENSE TYPE CAT

/0/1/ -

E g/ (6) /0/5/0/0/0/3/3/9/ (7) . /0/5/2/9/8/1/ (8) /0/6/2 /2 /s/1/ (9)

DOCKET NUMBER EVENT-DATE REPORT DATE EVENT DESCRIPTION AND PROBABLE CONSEQUENCES (10)

/0/2/- / On May 29', 1981 with Unit II at'100%' power, it was discovered during a surveil- /

/0/3/ / lance test that the summing amplifier for AT/Tavg Protection Channel I was' /

/0/4/ / reading high out of tolerance. This is non conservative with reference to '/-

/W J / _ / ESF (Engineered Safety Features) actuation for stes:a break protectio . Since /-

/0/6/- / two redundant AT/Tavg Protection Channels were 'available to initiate the proper / -

/0/7/ / ESF signal,'the public health and safety was not affected. /

/0/8/ / /

SYSTEM CAUSE CAUSE COMP. VALVE CODE CODE SUBCODE COMPONENT CODE SUBCODE SUBCODE

-/0/9/ /I/A/ (11) g/ (12) '/G/ (13)'/I/N/S/T/R/U/ (14) LQ/ (15) g/ (16)

SEQUENTIAL OCCURRENCE REPORT REVISION LER/R0 EVENT YEAR ~ REPORT NO. CODE TYPE NO.

(17) REPORT NUMBER /8/1/ -/-/- /0/4/5/ /\/. /0/3/ g/ /-/ L0, /

ACTION FUTURE EFFECT -SHUTDOWN ATTACHMENT NPRD-4 PRIME COMP. COMPONENT TAKEN ACTION ON PLANT' METHOD HOURS SUBMITTED FORM SUB. SUPPLIER- MANUFACTURER g/ (18) LZ/ (19) g/ (20) LZ/ (21) /0/0/0/0/ (22) /_Y/ (23) [N/ (24) LN/ (25) /W/1/2/0/ (26' CAUSE DESCRIPTION AND CORRECTIVE ACTIONS (27)

/1/0/ / The cause of this occurrence was attributed to instrument drift. /

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/1/3/ / /

'/1/4/ / /

FACILITY METHOD OF STATUS  % POWER OTHER STATUS DISC 0ERY DESCRIm0N (32)

/1/5/ LE/ (28) /0/0/0/ (29) / NA / (30) DISC 0ERY/ Surveillance

/_B/ (31) Testing /

l ACTIVITY CONTENT RELEASED OF RELEASE AMOUNT OF ACTIVITY (35) LOCATION OF RELEASE (36)

-/1/6/~ g/ (33) LZ/ (34) / NA / / NA /

PERSONNEL EXPOSURES l NUMBER TYPE DESCRIPTION (39)

I

/1/7/ /0/0/0/ (37) /Z/ (38) / NA /

PERSONNEL' INJURIES NUMBER' DESCRIPTION (41)

/1/8/ /0/0/0/ (40) / NA /

L LOSS OF OR TYPE DAMAGE TO FACILITY (43)

DESCRIPTION

/1/9/ /Z/ (42) / NA /

PUBLICITY ISSUED DESCRIPTION (45) NRC USE ONLY

/2/0/ /N/ (44) / NA /////////////

NAME OF PREPARER W. R. CARTWRIGHT PHONE (703) 894-5151 i

90.h. _ . _ ._ _ _ _ . _ _ . _ . _ _ _ . _ . _ _ . _ , . _ _ _ _ _,

- e.@

Virginia Electric and Power Company North Anna ' Power Station, Unit //2

Attachment:

Page 1 of 1 Docket No. 50-339 Report No. LER 81-045/03L-0 Description of Event On May 29,.1981, with Unit II at.100% power in Mode I, the AT/Tavg Protection Channel I periodic surveillance test showed that the as found data for summing amplifier TM-412K was high out of tolersace by a sum of

= 643 MVDC or approximately 6.43'F. - This data obtained was non-conservative in.that the Low-Low Tavg portion of the Engineering Safety. Feature actuation (Steam Flow in Two Steam Lines -- High Coincident with Tavg -- Low-Low or

- Steam Line Pressure-- Low) would have had to decrease an additional 6.4*F.

(for the affected channel only) in order to actuate that portion of the signal. This event is contrary to T.S. 3.3.1.1 and reportable. pursuant j to T.S. 6.9.1.9.a.

Probable Consequences of Occurrence Since two redundant channels were available to initiate the Low - Low Tavg portion of the above referenced ESF actuation the public health and

- safety were not affected.

Cause of Event The cause of this event is attributed to instrument drift.

Immediate Corrective Action The summing amplifier was recalibrated in accordance with the appropriate instrument calibration procedure and the entire channel j restored to normal operating status upon completion of the surveillance test.

Scheduled Corrective Action No corrective action is scheduled.

Actions Taken to Prevent Recurrence No further corrective action is scheduled.

Generic Implications There are no generic implications to this event.

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